This text is taken from Courrier de la planete. To subscribe, Click here.
If it damns outdoor sports enthusiasts, the mild winter we are experiencing has at least the advantage of allowing Quebec households to avoid excessively high electricity bills. In fact, heating (and air conditioning) represents on average 54% of the electricity costs of a residence, according to figures from Hydro-Québec.
A reader, Sylvie Méthot, wonders “if geothermal heating could not play a role as a source of renewable energy. We hear less about it now than we did a few years ago. I’m thinking, for example, of greenhouses: couldn’t they save a lot of money and polluting energy by converting to this technology (with possible subsidies to do so)? »
Let’s first define what geothermal energy is. Geothermal energy is a technology that uses the heat — or coolness — of the ground to heat or cool a building. Thanks to a system of pumps, a liquid is sent into an underground circuit installed several meters underground, the temperature of which changes on contact with that of the ground.
Can geothermal heating play a role as a renewable energy source?
Geothermal energy thus makes it possible in winter to extract the heat stored in the ground and transport it into the house. In summer, the process is reversed: the heat pump captures the heat present in the residence and sends it underground. The air returning to the house is thus naturally cooled by its passage underground.
Hydro-Québec indeed considers this technology as clean and renewable energy. According to the state-owned company, it saves up to 65% of heating costs compared to an electric baseboard system.
Geothermal energy, however, comes at a price: it costs $20,000 to $40,000 to install a geothermal system in an average-sized home. The return on investment also varies depending on several factors, including the nature of the soil, the insulation of the house and the surface area of the building, but it is generally spread over a period varying from 10 to 20 years.
Funding
On the residential side, there are several subsidy programs to encourage the switch to a geothermal heating system.
This is particularly the case with Hydro-Québec’s LogisVert program, which offers $750 per 1000 BTU/h for the purchase and installation of a geothermal heat pump, which can represent 50% to 60% of the cost. total cost of the project, according to calculations by Protégez-vous magazine. In terms of money, we are talking about financial support ranging from $10,000 to $24,000.
“Given the capital costs required, the main market is institutional and commercial,” estimates Cendrix Bouchard, spokesperson for Hydro-Québec. According to him, less than 1% of buildings in the province, for all uses, use geothermal energy.
For institutional, commercial and industrial customers, the Efficient Solutions and Innovative Projects programs also offer financial assistance to switch to geothermal energy, which varies depending on the size of the company.
A major obstacle
The low cost of electricity in Quebec is another obstacle to a transition to geothermal energy, believes Philippe Pasquier, full professor in the Department of Civil, Geological and Mining Engineering at Polytechnique Montréal.
“As I often tell my students, if we succeed in making geothermal energy work in Quebec, we will be able to do it all over the world! We have additional challenges here, given the ridiculous electricity prices. »
According to his estimates, it is always profitable for an individual or a company to choose geothermal energy “as long as construction costs do not increase”. And with the arrival of LogisVert, “it will become very interesting”.
According to him, the share of geothermal energy in Quebec’s energy landscape is set to grow given that more and more consumers, for environmental reasons, are giving up natural gas heating.
The same movement is observed among companies that use natural gas during peak periods and seek to reduce their GHG emissions. Hydro-Québec, which will have to cope with the meteoric rise in energy demand over the coming years, has every interest in promoting the appearance of this technology on a larger scale.
Pilot projects have already been installed in schools that heated with oil, notably the Clé-des-Champs primary school in Mirabel.
As for greenhouses heated with geothermal energy, none yet exist in Quebec, but “the potential is there,” believes Philippe Pasquier, who also holds the NSERC Industrial Chair in Geothermal Energy on the integration of permanent column wells in institutional buildings.
The agricultural lands of “Montérégie, Suroît or the Mirabel region all have very interesting geological potential for geothermal energy”.